Answer
$A-2B=\begin{bmatrix}
9 & 2
\\
2 & 6
\\
3 & -10
\end{bmatrix}
$
Work Step by Step
Multiplying each element of $B=
\begin{bmatrix}
-3 & 1
\\
2 & -4
\\
-1 & 5
\end{bmatrix}
$ by $2,$ and then subtracting the result from $A=
\begin{bmatrix}
3 & 4
\\
6 & -2
\\
1 & 0
\end{bmatrix}
,$ then
\begin{align*}
A-2B&=
\begin{bmatrix}
3 & 4
\\
6 & -2
\\
1 & 0
\end{bmatrix}
-
\begin{bmatrix}
-3(2) & 1(2)
\\
2(2) & -4(2)
\\
-1(2) & 5(2)
\end{bmatrix}
\\\\&=
\begin{bmatrix}
3 & 4
\\
6 & -2
\\
1 & 0
\end{bmatrix}
-
\begin{bmatrix}
-6 & 2
\\
4 & -8
\\
-2 & 10
\end{bmatrix}
\\\\&=
\begin{bmatrix}
3-(-6) & 4-2
\\
6-4 & -2-(-8)
\\
1-(-2) & 0-10
\end{bmatrix}
\\\\&=
\begin{bmatrix}
3+6 & 4-2
\\
6-4 & -2+8
\\
1+2 & 0-10
\end{bmatrix}
\\\\&=
\begin{bmatrix}
9 & 2
\\
2 & 6
\\
3 & -10
\end{bmatrix}
.\end{align*}
Hence, $
A-2B=\begin{bmatrix}
9 & 2
\\
2 & 6
\\
3 & -10
\end{bmatrix}
.$
